1. Field of the Invention
When, in closed spaces, air is supplied by air supply and/or conditioning ducts, it is desired that irritating or harmful germs, in particular fungi, algae, microbes, viruses and the like, not be introduced into the space since they can harm the health or at least the comfort of persons present therein.
2. Description of Prior Art
A disadvantage of air filters is that they will generally be unable to completely remove such germs, so that the germs let through can develop further, and, when improving the filtering efficiency, the pressure drop over such filters will increase accordingly. In the case of moist and warm air, very favorable conditions for the growth of such germs can occur.
A good air disinfection is especially important when a substantial part of the air introduced into the closed space is recycled, as, for instance, in airplanes.
Eliminating germs with poisonous substances is not allowed in most countries, if these substances can reach the space in which persons are present.